Known in the art are high-speed explosive hammers having a stationary bed incorporating a load bearing frame supporting a lower die and a hammer cylinder having a hollow piston rod carrying a hammer body having an upper die coaxial with the lower die, the upper piston chamber of said main hammer cylinder comprising an explosion chamber.
In the prior art hammers, the hammer body comprising a slab is rigidly fixed to the free end of the hollow piston rod and has relatively large mass, and a width which is greater than the width of the lower die. Therefore, the blank being treated is acted upon by the mass which is equal to a sum of masses of the piston, piston rod and the hammer body with the upper die. The piston and the hollow piston rod are moved during the work stroke under the action of pressure of gases released upon a blow-up of an explosive in the explosion chamber.
The piston is returned back into the initial position by means of two hydraulic cylinders mounted in the bottom portion of the load bearing frame. Piston rods of these cylinders bear with their free ends against the lower side of the slab upon liting the piston to the initial position thereby defining relatively large width of the slab, hence its great mass.
To provide optimum conditions for the manufacture of high-grade details by high-speed extrusion, pre-set values of velocity and impact energy should be ensured which are determined by density and ductility of the material of a blank being treated, as well as by shape and size of the part.
In known hammers, required impact energy may be obtained by selecting appropriate components of an explosive and the value of pressure under which the explosive is fed to the explosion chamber. It is, however, impossible to provide relatively high impact velocity with relatively small value of impact energy required for the manufacture of small parts due to comparatively large mass of elements acting on the blank upon deformation thereof. It is also impossible to provide relatively small impact energy with relatively high impact velocity in the manufacture of the same parts.
Therefore, prior art hammers cannot provide for the manufacture of parts of varying size thus limiting the manufacturing capabilities of such hammers.